Differential mechanism



May 25, 1937. R. L. szwEDA DIFFERENTIAL MECHANISM Filed sept. 12, 193e 2 Sheets-Sheet l INVENTOR mN NN mw RUFIN L. SzwEDA mmm wm Mmmm ATTORNEYS May 25, 1937.

R. L. szwEDA DIFFERENTIAL MECHANISM Filed sept. 12, 193e 2 Sheets-Sheet 2 INVENTOR RuFm L. Szwl-:DA

ATTORNEYS Patented May 25, 17937/ UNITED STATES PATENT OFFICE 2 Claims.

This invention vappertains to motor vehicles, and `more particularly to a differential 'mechanism vfor the driving lwheels thereof.

One of the primary objects of my invention is the provision of a novel differential mechanism :for the drive wheels Vof a motor vehicle, whereby the usual complicated system of gears and pinions will `be eliminated, and whereby a vsubstantially direct drive will be had between 'the Apropeller shaft andthe wheel -stub shafts 'or axles.

Another salient object of my invention is 'to provide va novel drive mechanism between the propeller shaft and the 'stub 'axles in Awhich the -axles are permitted independent rotation from one another incident to the wheels turning around a curve, both'during forward and `backward movement of the vehicle, the construction Lbeing such `that a positive drive will Vbe had fon Vthe `rear wheels, even if traction is had only on `one wheel.

A'further important object of my invention is to provide a differential drive mechanism for 'independent stub axles and an intermediate `drive shaft vcarrying clutch sections having opfrotationof the stub axles, both on forward and reverse travel of the vehicle when said axles tend Vto rotate fasterthan `the engine of vthe vehicle.

With these and other `objects in View, the invention consists in the novel construction, arrangement, and formation lof parts, as will be hereinafter more specifically described, claimed, and Aillustrated in the accompanying drawings, in which drawings:

Figure 1 is a fragmentary horizontal section through my novel differential drive mechanism.

Figure 2 is an enlarged, fragmentary detail view of the clutch utilized during the backing of the vehicle.

Figure 3 is an enlarged, fragmentary plan view illustrating the clutch utilized during the forward movement of the vehicle.

Figure 4 is an enlarged, detail transverse secdrive shaft 2 I, on opposite sides of the clutch sec- (Cl. 'r4-389.5)

tion taken on the vline 4-4 of Figure 1, looking 'in the direction of the arrows.

Figure 5-is an enlarged, fragmentary sectional view illustrating the novel mechanism employed for shifting the intermediate ldrive shaft, and for connecting the intermediate drive -shaft with one stub axle.

Figure 6 is a detail section on an enlarged scale through the intermediate drive shaft taken on -the line 6 6 of Figure 5, looking in 10 Vthe direction of the arrows.

"Figure 7 is a similar view taken on the line 'I-I of Figure 5, looking in the direction of the arrows.

Figure 8 -is -an enlarged, detail sectional view 15 through `the -drive gear for the intermediate drive shaft.

Referring to Ithe drawings in detail, wherein similar reference characters designate corre-i `spending `parts throughout the several views, the 20 letter M `generally indicates my improved differential mechanism, which comprises a stavtionary housing Ill ofthe desired formand shape.

Extending into the housing l0 is the propeller shaft I '-I. Suitable bea-rings "I2 are provided for 25 -the shaft I I, and these bearings can 4be of the roller or ball-bearing type, if preferred. g

Rotatably mounted within the housing I0 is a transversely extending counter-shaft I3 operatively connected to the propeller shaft in any preferred manner, such as through the use of beveled gears I4 and I5. Extending into the opposite ends of the lhousing are rotatable stub axles I6 and I'I. Any preferred type of bearings can be provided for supporting the stub axles, 3 and the outer ends of these axles carry the usual ground wheels (not shown). The inner ends of the stub axles I6 and Il are provided with elongated sleeves I8 and I9, for a purpose which -will be later set forth, but it is to be noted at this time that the ysleeve I8 `is of a greater size than the sleeve I9, and that the sleeve f9 terminates in a nut 20.

Between the vstub axles I6 and I'I is an intermediate drive shaft 2I. One end of the drive shaft extends into the sleeve I8, and the other end of the drive shaft is threaded, as at 22, and a part of said threaded portion is fitted into the nut 20.

Securely bolted or otherwise connected to the inner end of the sleeve I8 is a clutch section 23 having clutch faces 24 and 25 on its opposite sides. The teeth of these faces are inclined in opposite directions. Secured to the intermediate tion 23, are clutch sections 26 and 21, which are adapted to engage the clutch sections 24 and 25 at certain times. The clutch section 21 is adapted to engage the clutch face 25 during the forward driving movement of the vehicle, and the clutch section 26 is adapted to engage the clutch face 24 during retrograde movement of the vehicle.

The clutch section 26 has a' limited sliding movement on the shaft 2l and an expansion coil spring 26 is employed for normally urging the clutch section 26 in the direction of the clutch face 24. The clutch section 21 also has limited sliding movement on the shaft 2 and is normally urged toward the clutch face 25 by an expansion coil spring 29. It is to be noted that the spring 29 bears against a stop collar 3, which forms an important part of the present invention.

Arranged in spaced relation to the stop collar 30 is a second stop collar 3l, and the portion of the shaft 2l between the stop collars 3l and 3l is of a polygonal shape for slidably receiving the hub 32 of a drive gear 33. The drive gear 33 is formed on one end of the hub, and a stop ange 34 is formed on the other end of the hub. The hub is threaded, as at 35, between the gear and the stop flange, and these threads are adapted to be engaged by a stationary nut or an internally threaded ring 35 carried by the differential housing. The threads 35 are interrupted adjacent to the gear 33, so that the hub can run free in the nut when the hub and gear arefin one of their positions.

The gear 33 meshes with an elongated pinion 31 on the counter-shaft I3, and due to the shape of the pinion driving connection is permitted between the pinion and the gear during the sliding movement of the gear 33, as will be later set forth.

The threaded portion 22 of the shaft 2l has formed therein at spaced points annular grooves 38 and 39. Each of these grooves has formed therein stop shoulders 43 and 4I The stop shoulder 40 is oppositely disposed relative to the stop shoulder 4I. The sleeve I9 of the stub axle I1 carries a bracket 42, in which is slidably mounted a spring pressed latch pin 43. The latch pin 43 is adapted to ride in the groove 39, and to engage the shoulder 4I, so as to bring about a drive between the shaft 2l and the stub axle I1 during forward movement of the vehicle. 'Ihe pin 43 is adapted to ride in the groove 38, and to engage the stop shoulder 4I) to bring about a drive between the shaft 2l and the stub axle I1 during retrograde movement of the vehicle.

From the description so far it can be seen that during forward movement of the vehicle, the propeller shaft II `will be turning in a clockwise direction (referring to Figure l), which will rotate the counter-shaft I3 in the opposite direc-v tion and bring about the driving of the intermediate drive shaft 2l through the .gear 33 and pinion 31.

Considering that the clutch section 21 is in engagement with the clutch face 25 and the pin 43 is in the groove 39, a direct drive will be had between the intermediate drive shaft 2 I and the axles I6 and I1. In going around a curve, should the axle I'I turn faster than the axle I6, then the pin 43, turning faster than the intermediate shaft 2l, will continuously ride over the inclined face of the shoulder 4I, allowing the desired differential movement. Should the axle I6 rotate faster than the axle I1 going around a curve, then the clutch face 25 will simply ratchet over the clutch section 21, allowing the desired differential movement.

Now, should it be desired to back the vehicle, the shaft 2i will be driven in a reverse direction. The pin 43 will engage in the threads 22 of the shaft, and the shaft will be fed to the right until the pin rides into the groove 33. This movement of the shaft will carry the clutch section 21 away from the clutch face 25, and will carry the clutch section 26 into engagement with the clutch section 24.

In turning a curve, should the axle I1 rotate faster than the axle I6 and the shaft 2 I then the pin 43 will ride over the inclined face of the shoulder 46, allowing the desired differential movement. If the axle I6 rotates faster than the axle I1 and the shaft 2l, then the clutch section 26 will simply ratchet over the clutch face 24. When the vehicle is again started forward, then the shaft 2l will again be rotated in a clockwise direction, and the pin 43 will engage the threads at the right of the groove 38, and the shaft 2l will be shifted until the pin 43 rides into the groove 39 and the clutch section 21 engages the clutch face 25.

Between the grooves 38 and 39 is a pair of spaced annular grooves 44 and 45.

If the vehicle is going forward and both of the wheels tend to rotate faster than the engine, then the threads on the nut 36 will catch the threads 35 on the hub 32, and the gear 33 will be fed to the right until the nut rides into the groove 36' formed in'the hub adjacent toI the flange 34. Further movement of the hub is prevented by the engagement of the flange 34 with the nut.

During the slidingk movement of the hub, the shaft 2l will be shifted to the right. Consequently, the pin 43 will ride on the threads 22 of the shaft ZI until the pin reaches the groove 45, where the pin is permitted to turn freely. 'I'he pin will reach the groove 45 when the flange 34 engages the nut.

When direct drive from the engine is resumed, then the threads on `the nut 36 will catch the threads 35, and the gear will be moved to the left until the pin 43 again reaches the groove 39.

If the vehicle is being backed and the axles I 6 and I1 tend to run faster than the shaft 2|, the same movement will take place, and the pin 43 will ride from the groove 38 into the groove 44. During this action the clutch section will be in engagement with its clutch face, due to the limited movement allowed each clutch section on the drive shaft 2|.

If desired, the gear 33 and the flange 34 can carry spring pressed push and wear plates 46, as shown in Figure 8 of the drawings. These plates will give the desired impulse to the hub to insure the catching of the threads on the hub with the threads on the nut or ring 36.

Changes in details may be made, but what I claim as new is:

l. In a differential mechanism, a propeller shaft, a pair of independent stub axles, an intermediate drive shaft, means operatively connecting the propeller shaft with the drive shaft, a clutch section connected with one stub axle having clutch faces on its opposite ends provided with oppositely inclined teeth, spaced clutch sections on the intermediate drive shaft for engagement at different times with the clutch faces, 'said intermediate drive shaft having a threaded portion provided with spaced grooves vso having oppositely directed stop shoulders therein,

and a spring pressed pin carried by the other stub axle for engagement in said grooves at diierent times and for engaging the thread at another time to shift said drive shaft.

2. In a differential mechanism, a propeller shaft, a pair of independent stub axles, an intermediate drive shaft having a polygonal portion intermediate its ends, a drive gear on said polygonal portion for longitudinal movement, a counter-shaft, means operatively connecting the counter-shaft with the propeller shaft, an elongated pinion on the counter-shaft meshing With the gear on the intermediate drive shaft, said gear having a threaded hub provided with annular grooves at each end thereof, and stops beyond the grooves, a stationary nut adapted to normally ride in either one of the grooves and for engagement with the threads to shift the gear at a predetermined time, a clutch section carried by one stub axle having clutch faces at its opposite ends provided with oppositely directed inclined teeth, spaced clutch sections on the drive shaft for engagement with the clutch faces at different times, said last mentioned clutch sections having limited sliding movement on the drive shaft, the drive shaft adjacent to the other stub axle being provided with spaced grooves having oppositely directed shoulders, a spring pressed pin carried by the last mentioned stub axle for engagement in said grooves at different times and for engagement with the thread on said drive shaft at another time to shift said drive shaft, and said drive shaft having spaced annular grooves intermediate the rst mentioned grooves to receive said pin upon the shifting of the drive gear.

RUFIN L. SZWEDA. 

